None.
Not applicable.
The present invention generally relates to racks for supporting workpieces in industrial coating operations and more particularly to a rack design that permits numerous modes of assembly.
Industrial coating systems employ a conveyor from which workpieces are hung on support racks and are conveyed through several stations, usually including stations for performing the steps of cleaning, rinsing, drying, coating, and baking, often including repeats of these steps and often in a different order. In many industrial coating operations, the workpieces travel through an electrostatic coating booth wherein the electrically grounded workpieces are sprayed or coated with electrically charged coating particulates, either liquid or powder. After coating and baking, the coated workpieces are removed from the racks and the racks are reused for another coating cycle. Because of the recycling of the racks, they become coated and encrusted with multiple layers of the coating material. It is important in those instances where electrostatic coating is employed that the support rack be electrically conductive so that workpieces can be maintained in a grounded state. The workpieces are electrically connected to ground through a conductive support rack so that electrically charged particulates are attracted to the workpieces by the electrostatic field.
During each coating cycle, a layer of coating is applied to all exposed electrically conductive surfaces, including the support rack. Unless identical workpieces are coating during each coating cycle, the support racks need to be disassembled for cleaning and reassembly for the next workpiece to be coated. Thus, flexibility in support rack assembly, disassembly, and reassembly is a desired feature.
Heretofore a variety of support rack assemblies have been proposed in the art. U.S. Pat. No. 6,189,709 proposes an electrically conductive rack, which has a crossbar attached to the vertical beams using the open Z-folded end, including a threaded rod and nut assembly (FIG. 4), an S-hook (FIG. 5), vertical wires inserted in an aperture (FIG. 6); and a flat tongue (FIG. 7). U.S. Pat. No. 5,908,120 proposes to attach a vertical rod to the crossbar via an aperture that penetrates vertically through the crossbar. U.S. Pat. No. 5,897,709 proposes to attach an upper horizontal crimped area of the crossbar with a hole to vertical J-hooks that serve as the vertical rod. U.S. Pat. No. 5,531,334 proposes to attach the flat end of the crossbar to the vertical rod with a threaded fastener or rivet (FIG. 7). U.S. Pat. No. 5,524,774 proposes to use holes in the vertical rod to engage elongate hooks for supporting the crossbar. U.S. Pat. No. 5,147,050 proposes to use holes in the vertical rod and spaced-apart fingers of a bracket to support the crossbar. U.S. Pat. No. 5,020,677 proposes to rest the crossbar on supporting fingers extending from the vertical bars wherein spring clips or the like retain the crossbar on the fingers. U.S. Pat. No. 4,899,966 shows an integral crossbar and vertical bar assembly (FIG. 5). U.S. Pat. No. 4,628,859 shows a coat hanger for hanging parts from. U.S. Pat. No. 4,097,359 shows a rectangular bar assembly where the upper and lower crossbars and attached to the left and right vertical bars by xe2x80x9cwelding, bolting, etc.xe2x80x9d U.S. Pat. No. 4,097,359 proposes a rectangular bar assembly where the supporting hooks are inserted into U-shaped horizontal bars. U.S. Pat. No. 5,762,205 proposes to hang the horizontal crossbars to vertical channel beams with hooks that protrude from the beams and which fit into the U-shaped crossbars. U.S. Pat. No. 4,037,727 proposes a vertical bar that fits through vertically oriented apertures in the crossbars wherein a thumbscrew holds the bar in position.
It is to a rack assembly with unique design for assembly by a diverse number of mechanisms that the present invention is directed.
An support rack system, which may be made electrically conductive, has one or more generally horizontal crossbars. Each crossbar has a front face and a spaced-apart rear face. Each of the crossbar faces is interconnected at one or more spaced-apart locations to reveal at least one pocket. The crossbar faces are matingly connected adjacent at least one of the pockets. The mating connection of the crossbars has at least one aperture penetrating therethrough. The rack system also has one or more generally parallel, vertically oriented support bars. At least one of the support bars bears a mechanism adapted to attach said crossbars to said support bar with one or more of the crossbar aperture or the crossbar pocket.
Another aspect of the present invention is a method for assembling a support rack system. This method commences with providing one or more generally horizontal crossbars. Each crossbar has a front face and a spaced-apart rear face. Each of the faces are interconnected at one or more spaced-apart points to reveal pockets between the points. The faces are conformingly pinched together adjacent to at least one of the pockets. The pinch has at least one aperture penetrating therethrough. One or more generally parallel, vertically oriented support bars also are provided. At least one of the support bars bears a mechanism adapted to attach the crossbars to the support bar using one or more of the crossbar aperture or the crossbar pocket. Finally, one or more crossbars are attached to the one or more support bars with the mechanism attached to one or more of the crossbar aperture or the crossbar pocket.
A further aspect of the present invention is a method for industrial coating of workpieces hung from support racks which racks are affixed to a conveyor. The first step is to provide the support rack system. Then a workpiece is hung from at least one of the crossbars. The rack system is hung from a conveyor. Finally, the workpiece is subjected to industrial coating, e.g., electrostatic powder coating, oil coating, latex coating.
Advantages of the present invention include a rack system design that is easy to assemble. Another advantage is a rack system that can be manufactured to be easily disassembled. A further advantage is a rack system that can be assembled using a variety of mechanisms. Yet another advantage is a rack system that can be configured into a variety of patterns. These and other advantages will be readily apparent to those skilled in this art based upon the disclosure set forth herein.